Lengthening a throat? Lead angle for VLD’s?

[ImBIllT]

Is there a decided upon best lead angle for VLD’s?

Might lengthen a throat on a 6.5-257. Is it highly difficult to do so in-line with the chamber using just a throater? I realize that is commonly done, but is it considered risking poor accuracy when compared to using a chamber reamer with the desired throat already on it? Assuming that’s not a potential problem, should I mount the barrel back in the lathe like a chamber job, or is a uni-throater something one can be highly confident in? Thanks!

 

[Scott Harris]

It's quite easy. Find a decent smith and you are good to go.

 

[ImBIllT]

It's quite easy. Find a decent smith and you are good to go.

Will be doing it myself with a uni-throater, or letting my dad do it in a lathe. He was a machinist for part of his working life, and has chambered his share of barrels, but has never done just a throat. Obviously he gets the gist of it, but we’re definitely wondering if it’s just as likely to be accurate as using a chamber reamernwib the desired free-bore, and if a uni-throater is just as good, it would certainly be easier than removing the barrel and indicating it in.

 

[Scott Harris]

Have your dad dial the barrel in alignment with the existing chamber and run the unithroater in. The hard part on a used barrel is finding where the lands currently reside. If you have a borescope, that helps to check the work. If not, you can use a dummy round seated in the desired position and then carefully run the unithroater a little longer each time until the round fits with no resistance. Check Alex Wheelers seating depth videos for that technique.

 

[6MMsteve]

I done mine by hand 3 of them the instructions from ptg say to run the throater in slowly turning it in reverse to find the lands, that would be using the lock nuts on the UNI rig and going in and out till you touch the lands kinda scary at first when you start cutting use lots of oil then set the throater and cut .020 at a time that's what i done, it would be very easy in a lathe,I cut mine 0.020 then cleaned and recoated with oil stayed with the process till I hit my desired length. I done mine by hand using a dummy tang bolt with a radius cut to level the throater and kinda guide it, I checked later with borescope and it was cut fairly square, with a lathe and barrel trued or centered it would be easy I think, then I went in with a little J&B and kinda polished the area lightly. but there are others on here that have forgot more than I will ever know about barrel machining.

 

[Shawnba67]

The uni throater is a slick tool. A bit $$$
I made this set up from aluminum to fit my Manson throater. The small piece has a slight taper to center in rear of chamber, the inside was bored true to a slip fit on reamer shank. All done in one set up on lathe. The big collar acts as an adjustable stop and turning handle. If you set the diameter correctly and used a short grub screw to hold it you could use the long T wrench through the action. If you were careful and steady of hand you could get by without the stop. This should keep you all in line with existing chamber.

Is there a decided upon best lead angle for VLD’s?

Might lengthen a throat on a 6.5-257. Is it highly difficult to do so in-line with the chamber using just a throater? I realize that is commonly done, but is it considered risking poor accuracy when compared to using a chamber reamer with the desired throat already on it? Assuming that’s not a potential problem, should I mount the barrel back in the lathe like a chamber job, or is a uni-throater something one can be highly confident in? Thanks!